Weather is a major cause of extreme damage and human injury. Hurricanes and tropical storms, prolific on the east coast and gulf coast of the United States, particularly in Florida, are examples of weather occurrences that wreck havoc with buildings. Many building codes, particularly in hurricane-prone areas, require that doors and windows in habitable structures meet strict structural design parameters. The structural integrity of doors, windows and exterior cladding elements is strictly governed by these codes.
It is now understood that the garage door, in residential applications, is a large factor in the amount of structural damage experienced by the entire structure. When a garage door fails under wind load, the effects are usually devastating to the entire building. A garage door has a relatively large exposed area (typically at least 72 sq. ft) in proportion to the enclosure. When the door fails under high wind load, the resultant sudden pressurization of the enclosure often results in complete destruction of the building.
New code requirements, especially in south Florida, have generated a rapidly growing industry in hurricane-resistant building envelopes and components.
There are several main performance criteria directed to doors and windows, for example “impact resistance,” “structural load capacity,” “cyclic resistance,” and “uniform static air pressure resistance”. Impact resistant performance criteria recognize the need for resistance to windborne debris, which can cause catastrophic damage when striking a door or window under structural load.
One alternative to installing either impact resistant or high wind resistant components into building openings has been to “shutter” the opening with structurally designed and approved devices that are physically placed over the opening prior to the high wind event. These shutter systems increase the door's resistance to impact from objects and to high pressures. However, because of the physical size of the garage door, the shutter system is cumbersome and expensive, and renders the garage unusable while “shuttered.”
Because of the aforementioned issues concerning the shuttering of garage door openings, a strong demand was present to provide a garage door with high impact resistance and high wind load performance inherent in its design. Further, the insurance industry and building code enforcement entities are particularly interested in garage door products that do not require shuttering. The state of Florida has passed building code protocols TAS 201, 202 and 203, and Miami-Dade county has testing protocols PA-201, PA-202 and PA-203, which set the standard wind load resistance of −65 psf and +48 psf for large missile impact garage doors.
Currently, there are no products that meet the construction standards yet provide an aesthetic, customized wood door. The typical designs used in sectional garage doors to offer high wind load performance are based on a standard metal door incorporating any number in integral reinforcing devices in the door assembly or as external attachments. These metal doors generally do not offer load rated windows. The flexibility of design is extremely limited in the current products. Improvements are desired.